Thanks to all who replied
The Hagan paper sited in the ARRL Antenna handbook was eventually
located and turned into a scavenger hunt. Hagan published several papers
on the subject and the math for using the OWL probe approach is in yet
another paper by Hagan.. (publish or perish I guess).
As it turns out the Rudy N6LF has a much easier path to follow ( should
have known ..tnxs Rudy). At any rate I eventually Googled my way back to
Rudy's home page and then subsequently to this page.
https://www.antennasbyn6lf.com/measurement_of_soil_characteristics/
( Tnxs to Carl K9LA who clued me into the N6LF papers to begin with)
Towards the bottom of this page is a section titled "Soil parameter
measurements at HF", and at the bottom of that paragraph is a link
highlighted in blue "ground parameter measurements
<https://www.antennasbyn6lf.com/files/ground_parameter_measurements_2.pdf>"
which in turn takes you to a paper by Rudy which among other things
addresses the construction and math involved in an OWL ( open wire line)
Probe.
For those of you who have a decent VNA the assembly and use of an OWL
probe is discussed. Not for everyone depending on your soil type (and
the time of year for you guys in Minnesota) but for my sand bar in
Florida just what the doctor ordered, Also the need for a BALUN should
be noted if your VNA is connected to the power mains eventually as the
all that becomes part of your "ground" if not isolated from the
measurement field.
73
Dave
NR1DX
manuals@artekmanuals.com
On 2/13/2021 12:59 PM, Artek Manuals wrote:
In the process of trying to correlate actual measured R+jX values vs
NEC models for an 80M inverted L with elevated radials, I was directed
to a paper by Rudy N6LF in QEX from 2009. I have used Rudy's approach
and have after many iterations achieved reasonable correlation between
actual and modeled numbers. The numbers were not what I expected but
are "believable"
It would be intellectually far more satisfying to be able to measure
conductivity and dielectric values through direct means.The ARRL
Antenna Handbook ( 22nd edition , page 3-21) references some work done
by George Hagan back in the 1980's using probes and a VNA. . The ARRL
in its infinite wisdom of course does not show the math involved in
using this method to directly measure and calculate conductivity and
dielectric constant. I have "probes" and a decent VNA ( AIM4300)
I am looking for a copy of:
HF Ground Measurements at the Lawrence Livermore National Laboratory
Field Site; /Applied Computational Electromagnetic's Society Journal
and News Letter, Vol. 3,Number 2, Fall 1988"
/
Any help appreciated with either a copy of the paper or a pointer to
where it might be downloaded. So far Google has not been my friend./
Dave
NR1DX
manuals@artekmanuals.com
/
--
Dave Manuals@ArtekManuals.com www.ArtekManuals.com
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